Diabetes is a disease in which the function of insulin becomes insufficient, the blood glucose level becomes high, and sugar is detected even in urine. Insulin is produced in and secreted from pancreatic β cells, promotes synthesis of glycogen (storage type glucose) from glucose in the liver and muscle, suppresses degradation of glycogen into glucose in the liver, and suppresses increase in the blood glucose level.
The number of patients is increasing mainly due to overeating, lack of exercise, obesity, stress, and genetic factors.
Diabetes is largely divided into type 1 diabetes showing absolute lack of insulin, and type 2 diabetes showing relative lack of insulin. Type 1 is basically treated with insulin injection, and type 2 is basically treated with diet and exercise therapy, though drug therapy is necessary when the blood glucose cannot be controlled well. For drug therapy, oral therapeutic drug for diabetes or insulin is used, both of which require improvement in terms of side effects, QOL and the like.
In addition, the condition developing lifestyle-related diseases such as hypertension, hyperlipidemia, diabetes and the like due to the accumulated visceral fat is referred to as metabolic syndrome, and has been widely recognized to increase the risk of developing arteriosclerotic diseases (myocardial infarction, cerebral infarction etc.). Accordingly, the prophylaxis or treatment of diabetes is necessarily effective for the prophylaxis or treatment of metabolic syndrome.
Phospholipid has various biological activities and, for example, a certain kind of phospholipid has been reported to be effective for the improvement of cognitive function and neurodegenerative disease. For example, 1,2-dilinoleoyl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine have been reported to improve spatial learning disorder and memory disorder induced by scopolamine, or mild cognitive impairment and dementia (non-patent documents 1, 2).
Also, phosphatidylethanolamine is a phospholipid, which is one of the main components of biological membrane, and is being marketed along with phosphatidylserine and the like as health foods. Of phosphatidylethanolamines, particularly, dilinoleoyl phosphatidylethanolamine (containing two linoleic acids as fatty acids) has been reported to have cell death induction suppressive activity, particularly, endoplasmic reticulum stress suppressive activity and, due to such activity, dilinoleoyl phosphatidylethanolamine can be used for pharmaceutical application, particularly for the prophylaxis and/or treatment of neurodegenerative disease (patent document 1).
In addition, phospholipid used for biological membrane model, liposome preparation and the like has also, been reported.